The prior art includes a number of blade mounting assemblies for bull dozer blades. These blade mounting assemblies are not satisfactory for relatively small tractors or dozer implements wherein it is preferable to mount a dozer blade close to an implement frame for stability and ease of handling.
Besides positioning the dozer blade close to the implement frame, a blade mounting apparatus on a small implement should mount the blade in a manner permitting varied motions, i.e., raising, lowering and angling of the blade with respect to predetermined reference planes. The blade mounting apparatus should allow the dozer blade to angularly move at least 35.degree. in opposite directions about a vertical axis while maximizing blade offset (the lateral distance the blade laterally extends beyond the wheels) in a fully angled position.
J. I. Case Company manufactures and sells wheeled trenchers with a dozer blade attached thereto. The trencher dozer blade is most commonly used in backfilling operations. A conventional blade mounting apparatus on a wheeled trencher includes a pivotally movable blade mounting frame with the dozer blade connected to a forward end thereof. Angular movement of the blade mounting frame is controlled by a linearly distendable driver which extends in a fore-and-aft direction relative to the implement frame.
The driver is typically in the form of a hydraulic cylinder. The cylinder end of the driver is connected to the implement frame and a movable piston end of the driver is connected to the blade mounting frame to one side of a pivot connection about which the mounting frame angularly moves. As will be appreciated, the fore-and-aft orientation of the cylinder tends to elongate the mounting frame design and moves the blade away from the implement frame. Moreover, arranging a linearly distendable driver generally parallel to the implement frame for angling the dozer blade detracts from the driving force imparted to the blade upon extension of the driver.
Thus, a need and a desire remains for a blade mounting apparatus which allows for extended angling and vertical movement of the blade while minimizing the distance between the dozer blade and frame of the implement.